Vacuum distillation apparatus



July 16,1946. K. c. D. HlcKMAN ET Al. 2,403,978

` VACUUM DISTILLATION APPARATUS Filed Sepl'.. 12, 1944 INVENTORS um/ EDM OND S PERRY KENNET .n.HICKMaN D/sT/LLATE our UND/5mm@ Res/puf our ATTORNEYS Patented July 16,1946

VACUUM DISTILLATION APPARATUS Kenneth C. D. Hickman and Edmond S. Perry,A Rochester, N. Y., assignors to Distillation Prod- `ucts, Inc., Rochester, N. Y., a corporation of Delaware Application September 12, 1944, Serial No. 553,688

High-vacuum Vunobstructed path distillation.

apparatus with stationary vaporizing and ,condensing surfaces is well known. Such apparatus has the definite disadvantage that distilland cannot be distributed onthe vaporizing surface in a sufficiently thin nlm. The distribution takes place 9 Claims. (Cl. 202-205) lli by gravitational ow and this limiting factor rev sults in films of relatively great thickness. Since distillation takes place from the surface of the lm only such thick films give poor distillation and considerable thermal decomposition. It has s proposed'previously that the distilland be V-tstributecl on the vaporizing surface by centrifugal force. This representeda distinct advance in the art. However, construction of large rotating vaporizing surfaces is not a simple problem. The gravitational flow type of still heretofore used has had the distinct advantage of simplicity and low eeft of construction.

This invention has for its object to provide a vacuum unobstructed path still having astationary vaporizing surface which is simple and economical to construct, and which enables distribution of distilland thereon in a lm substantially thinner than'obtained by gravitational iiow. Another object is to provide vacuum unobstructed path distillation apparatus in which the surface of the distilling film is rapidly renewed. A further object is to provide improved vacuum unobstructed path distillation apparatus. Other objects will appear hereinafter.

These and other objects arel accomplished by my invention which includes vacuum distillation apparatus provided with a stationary vaporizing surface, a condensing surfaceV separated therefrom by substantially unobstructed space and means, which oder relatively little resistance to the flow of vapors, for distributing and rapidly renewing the film of distilland, which means is positioned between the vaporizing and condensing surfaces.

In the following description we have set forth several of the preferred embodiments of our invention but it is to be understood that these are given by way of illustration and not in limitation thereof. l

In the accompanying drawing we haveillustrated a preferred embodimentof our invention wherein: j

rFig. 1 is aV vertical section of a still provided A 2 with means for distributing distilland on thestationary vaporizingsurface: f

Fig. 2 is a horizontal section of Fig. l, and

Fig. 3'is a vertical section of l a slight modification illustrating the use of distributingy means to offer even less 'resistance to the flow of vapors than that shown inFig. 1.v 4

Referring to Fig. l, numeral 6 designates a cylinder casing provided `with an annular recess gutter 8 in the lower `and i0 in the upper wall thereof. Numeral l2 designates an integralb'ase and numeral I4 a removable cover which makes a gas-tight connection by means of a gasketlls., Numerals I8 and 20 designate-Withdrawal conduits for removal of gases'from the distillation chamber. These conduits4 are connected to evacuating pumps (not shown).

Numeral 22 designates a shaft 'housed in a packed bearing 24. This shaftteminates inA an eight-spoked spider 26'and is provided atits lower' extremity with a hole 28. Numeral 30 designates a'bearing positioned near the centerof base plate l2 in which is housed shaft 32.l The upper portaken on line 2'-'-2 tion of shaft 32 is integral with an eight-spoked spider 34 similar to `26. Spiders 26 and 34 are connected by means of rods 36 to form a single integral rotating element including shaft 22, spider 26, rods 35, brushes 38,'spider 34 andshaft 32 as one integral unit. Rods 36 carry numerous wire bristles 38 which are sufficiently long to impinge upon the inside wall of still casing 6,.' Y t Numeral 4l! designates a cylinder positioned inside the still casing 6 and approximately coaxial therewith. Cylinder 40 lis. provided with a double wall forming a tight jacket through which cooling fluid is circulated by introduction through conduit 42 and withdrawal through conduit 44. Shaft 45 is integral with the baseplate 48 of cylinder .0 and with plate l2 in the still andV serves to rigidly maintain cylinder 40 in the position illustrated. Numeral 50 designates a short shaft which protrudes into hole 2,8 and which is integral with plate 52 of the upper part of cylinder 40, and serves as a means for stabilizing cylinder 4t and maintaining it in theposition illustrated. Numerald indicates' an annular gutter integral with the base of cylinder 40 but which is connected to withdrawal conduit `Sli. Numeral 58 designates a conduit connected to the inside middle portion of casing 6 and numeral 60 designates a conduit connected to gutter 8 and numeral Y 62 designates a `conduit connected togutterY I0. Numeral 64 designates a pulley integral with shaft 221. Numeral 66 designates an 4insulating jacket surrounding casing 6 in which is positioned a heating element 63.

In operating the apparatus 'illustrated in Figs. 1 and 2 the system is evacuated through conduits I3 and 20. Heating element 68 is put into operation to heat the wall of 6 to distillation temperature. Force is applied to pulley 64 to rotate the brushes 38 and to cause them to pass Over the inside wall of 6. Cooling fluid is introduced into condensing cylinder 4i) and distilland is introduced through conduit 53 onto the inside wall .of S. This distilland is immediately spread by the brushes 38 upon the wall of .6 in a thin film which is rapidly renewed due to repeated wiping action of the bristles. The distilland is thus spread over the entire wall of 6 and this spreading action causes at least part of the distilland to travel upward against gravitational force and to pass into gutter l. Similarly, by a combination of the spreading action and gravitational force the remainder of the distilland, or rather the undistilled residue, passes into gutter 8.

During passage over the inside wall of 6 the film is heated to distillation temperature. V apors which are generated pass to the condensing surface 46 with relatively little obstruction. These vapors are then condensed to flow by gravity into gutter 43 and are withdrawn from the still through conduit 55. Undistilled residue is withdrawn through conduits 60 and 52.

The construction and operation of the apparatus illustrated in Fig. 3 is very similar to that illustrated` and described in connection with Figs. 1 and 2, the only difference being that two brushes 69 only are used and these are mounted on a two-spoked support 10. These brushes offer even less obstruction to the flow of vapors than the construction illustrated in Figs. l and 2.

It-isapparent that many modifications can be made in the apparatus illustrated without departing from the spirit or scope of our invention. Obviously the number of brushes 38 can be increased or decreased and obviously the rate of rotation can be varied to offset any change in the number of brushes, or to increase or decrease the spreading or filming action. Instead of heating by means of a Vhot coil Yas illustrated, it may be preferred in many cases to circulate hot combustion gases in the space between jacket 6B and the outside wall of casing 6. This would be a distinct advantage in that cheap sources of heat could be used.- While a brush constitutes the preferred form of distributing and renewing the surface of the distilland, this can be accomplished by othermeans such as wiper blades having sufi cient'tension as applied to the inside surface cf 5 to spread the distilland in the desired thickness. The bristles etc., should touch the vaporizing surface so that they wipe or smear the distilland into a thin film.

, What we claim is:

l. Vacuum distillation apparatus comprising in combination a stationary vaporizing surface, a condensing surface, said surfaces being separated from each other by substantially unobstructed space, means positioned between the vaporizing and condensing surfaces for mechanicallyV distributing distilland-onto the stationary vaporizing surface in the form of a thin film and for rapidly agitating and renewing said thin film by mechani- Kcal. action which means offers relatively little resistance to .the flow of vapors from the vaporizing to thecondensing surface, means for heating the vaporizing-surface, means for cooling the condensing surface, means for introducing distilland onto the vaporizing surface, means for removing undistilled residue from the vaporizing surface, means for removing distillate from the condensing surface and means for maintaining a vacuum in the space between the vaporizing and condensing surfaces.

2. Vacuum distillation `apparatus vcomprising in combination two hollow, stationary, approx1- mately eo-axial members one member serving as a vaporizing surface and the other serving as a condensing surface, said members being separated from each other by substantially unobstructed space, means ,for mechanically distributing distilland onto the stationary vaporizing surface in the form of a thin lm and for rapidly agitating and renewing said thin lm by mechanical action, which means offers relatively little resistance to the flow of vapors from the vaporizing to the condensing surface, means for heating the vaporizing surface, means for cooling the condensing surface, means for removing undistilled residue from the vaporizing surface, means for removing distillate from the condensing surfaceand means for maintaining a vacuum in the space between the vaporizing and condensing surfaces.

3. Vacuum distillation apparatus comprising in combination two hollow, stationary, approximately co-axial members having substantially parallel sides one member serving as a vaporizing surface and the other serving as a condensing surf-ace, said members being separated from each other by substantially unobstructed space, a movable brush adapted to .pass over the vaporizing surface distributing and renewing the lm of `distilland thereon during such passage, said brush offering relatively little resistance to the flow of vapors from the vaporizing to the condensing surface, means for heating the vaporizing surface, means for cooling the condensing surface, means for introducing distilland onto the vaporizing surface, means for removing undistilled residue from the vaporizing surface, means for removing distillate from the condensing surface and means for maintaining a vacuum in the space between the vaporizing and condensing surfaces.

4. Vacuuzn distillation apparatus comprising in combination two hollow stationary approximately co-aXial members having substantially parallel sides, one member serving as a vaporizing surface, and the other serving as a condensing surface said members being separated from each other by substantially unobstructed space, a rotatable brush which oifers relatively little resistance to the flow .of vapors between the vaporizing and condensing surfaces positioned so that during rotation the bristles thereof pass over the vaporizing surface and distribute distilland thereover in a thin, rapidly renewed nlm, means for heating the vaporizing surface, means for cooling the condensing surface, means for introducing distilland onto the vaporizing surface, means for removing undistilled residue from the vaporizing surface, means for removing distillate from the condensing surface, and means for maintaining a vacuum in the space between the vaporizing and condensing surfaces. v

5. Vacuum distillation apparatus comprising in combination a stationary vaporizinfI surface, a condensing surface positioned substantially opposite to and separated from the vaporizing surface by substantially unobstructed space, a rotatable brush which offers relatively little resistance tothe flow of vapors betweenthe Vaporizing and condensing surfaces positionedsothat, duringrotation, the bristles thereof pass over the vaporizing surface and distribute distilland thereover in a thin, rapidly renewed film, means for heating the vaporizing surface, means for cooling the condensing surface, means for introducing distilland onto the vaporizing surface, means for removing undistilled residue from the vaporizing surface, means for removing distillate from the condensing surface, and means for maintaining a vacuum in the space between the Vaporizing and condensing surfaces.

6. Vacuum distillation apparatus comprising in combination stationary vaporizing and condensing surfaces separated by substantially unobstructed space, which surfaces are approximately circular in cross section and co-axial with respect to each other, a rotatable brush which offers relatively little resistance to the flow of vapors positioned between said vaporizing and condensing surfaces so that it rotates on approximately the same axis as the vaporizing and condensing surfaces, and so that the bristles thereof during rotation pass over the vaporizing surface and distribute distilland thereover in a thin, rapidly renewed film, means for introducing distilland onto the vaporizing surface, means for removing undistilled residue from the vaporizing surface, means for heating the vaporizing surface, means for cooling the condensing surface, means for removing distillate from the condensing surface, and means for maintaining a vacuum between the vaporizing and condensing surfaces.

7. Vacuum distillation apparatus comprising in combination stationary, approximately concentric, cylindrical vaporizing and condensing surfaces, separated from each other by substantially unobstructed space which offers relatively little resistance to the flow of vapors between the vaporizing and condensing surfaces positioned so that, during rotation, the bristles thereof pass over the vaporizing surface and distribute distilland thereover in a thin, rapidly renewed film, means for heating the vaporizing surface, means for introducing distilland onto the vaporizing surface, means for removing undistilled residue from the vaporizing surfaces, means for cooling the condensing surface, means for removing distillate from the condensing surface, and means for maintaining a vacuum between the vaporizing and condensing surf aces.

8. Vacuum distillation apparatus comprising in combination a stationary, approximately cylindrical vaporizing surface, a stationary approximately cylindrical condensing surface of substantially smaller diameter than the vaporizing surface and positioned inside thereof and approximately co-axial therewith, a rotatable brush which offers relatively little resistance to the flow of vapors between the vaporizing and condensing surfaces positioned so that during rotation the bristles thereof pass over the Vaporizing surface and distribute distilland thereover in a thin, rapidly renewed lm, means for heating the vaporizing surface, means for introducing distilland onto the vaporizing surface, means for removing undistilled residue from the vaporizing surface, means for cooling the condensing surface, means for removing distillate from the condensing surface and means for maintaining a high vacuum in the space between the vaporizing and condensing surfaces.

9. Vacuum distillation apparatus comprising in combination an approximately cylindrical vaporizing surface, means for bringing hot combustion gases into contact with the outside of said cylindrical vapoiizing surface, a substantially cylindrical condensing surface of considerably smaller diameter than the vaporizing surface positioned inside the vaporizing surface and approximately co-axial therewith, a rotatable brush which offers relatively little resistance to the now of vapors between the vaporizing and condensing surfaces positioned so that during rotation the bristles thereof pass over the vaporizing surface and distribute distilland thereover in a thin, rapidly renewed lm, means for introducing distilland onto the vaporizing surface, means for removing undistilled residue from the vaporizing surface, means for cooling the condensing surface, means for removing distillate from the condensing surface. and means for maintaining a vacuum in the space between the vaporizing and condensing surfaces.

KENNETH C. D. HICKMAN. EDMOND S. PERRY.

Disclaimer 2,403,978.-Ke1meth C'. D. Hickman and Edmond S. Perry, Rochester, N. Y. VACUUM DISTILLATION APPARATUS. Patent dated July 16, 1946. Disclaimer filed Nov. 12, 1947, by the assignee, Dtstillat'ion Products, Inc. Hereby enters disclaimer to claims 1 and 2 of said patent.

[jicial Gazette January 6, 1948.] 

